McCharts and Multiclock FSMs for modeling large scale systems

Single-clock specifications with purely synchronous communication have been successfully used in capturing the behavior of small and medium scale embedded systems. In large scale embedded systems, where processes often operate at vastly different speeds, using a single clock in an entire specification can be difficult. In this paper, we present Multiclock Charts (McCharts), a language where finite state machines driven by different clocks are composed. The communication between FSMs is specified by both synchronous and asynchronous mechanisms. The essential feature in the semantics of McCharts is that a complete specification can be mapped onto a single multiclock FSM (MCFSM).